Gemini 4 Hydrogen vs GPT-5.6 Luna

Gemini 4 Hydrogen leads GPT-5.6 Luna on coding, 77.9 to 55.3 on the Vibe Coding Index, and GPT-5.6 Luna costs 6.3x less per output token ($1.20 vs $7.50 per million). Updated November 14, 2026; 41 benchmarks have a result for both.

Replace Gemini 4 Hydrogen Replace GPT-5.6 Luna

Gemini 4 HydrogenGoogle

Coding: 77.9
Overall: 77.1
Output $/M: $7.50

GPT-5.6 LunaOpenAI

Coding: 55.3
Overall: 57.1
Output $/M: $1.20

vs boards won of 41 shared

Gemini 4 Hydrogen or GPT-5.6 Luna: which to pick

Pick Gemini 4 Hydrogen for coding: it scores 77.9 on the Vibe Coding Index against 55.3 for GPT-5.6 Luna, though on 4 benchmarks against 5.

Pick GPT-5.6 Luna for output tokens 6.3x cheaper ($1.20 vs $7.50 per million) and a larger context window (1.05M against 1.05M tokens).

Model AGemini 4 HydrogenGoogle77.9/1004 independent benchmarksNo cost per solved task Model BGPT-5.6 LunaOpenAI55.3/1005 independent benchmarks$0.04 per solved task

41984

Shared results: 41
Gemini 4 Hydrogen only: 9
GPT-5.6 Luna only: 84
Like-for-like categories: 7 of 9

Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.

Which one for your work

Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.

Coding
Vibe Coding Index, six public coding benchmarks
Gemini 4 Hydrogen
Gemini 4 Hydrogen scores 77.9 against 55.3.
4 and 5 benchmarks behind the scores
Intelligence
AA Intelligence Index
No call
Only GPT-5.6 Luna has a AA Intelligence Index result, 23.8.
Directional only
Agentic work
AA Agentic Index
No call
Only GPT-5.6 Luna has a AA Agentic Index result, 42.1.
Directional only
Reasoning
GPQA Diamond
No call
Only GPT-5.6 Luna has a GPQA Diamond result, 91.7%.
Directional only
Knowledge
MMLU Pro
No call
Only GPT-5.6 Luna has a MMLU Pro result, 86.0%.
Directional only
Web design
Design Arena: websites
Gemini 4 Hydrogen
Gemini 4 Hydrogen leads, 1320 against 1248.
Same board, both measured
General
Vals Index
No call
Only Gemini 4 Hydrogen has a Vals Index result, 68.5%.
Directional only
Long documents
Listed context window
GPT-5.6 Luna
GPT-5.6 Luna takes 1.05M tokens against 1.05M.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
GPT-5.6 Luna
Gemini 4 Hydrogen $0.0053, GPT-5.6 Luna $0.0008 per turn.
List prices
Cost per solved task
One SWE-bench Verified task, solved
No call
Only GPT-5.6 Luna has the number, $0.04.
Directional only

At a glance

Coding index: Gemini 4 Hydrogen 77.9 from 4 benchmarks, GPT-5.6 Luna 55.3 from 5 benchmarks.
Widest category: Coding, 22.4 points apart on average over 10 shared benchmarks.
Widest single gap: Terminal-Bench 4 (Vals AI): Gemini 4 Hydrogen 54.0% against GPT-5.6 Luna 11.6%, 56.6 points apart on a 0 to 100 scale.
Output price: Gemini 4 Hydrogen $7.50 against GPT-5.6 Luna $1.20 per million output tokens, 6.3x apart.
Context window: Gemini 4 Hydrogen takes 1.05M tokens, GPT-5.6 Luna 1.05M.

Benchmark by benchmark

First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.

Boards won, where both have a result
Category	Gemini 4 Hydrogen	Bars	GPT-5.6 Luna	Ties
Coding	10		0
Agentic work	2		0
Reasoning	5		0
Math	2		0
Knowledge	5		0
Web design	4		0
General	13		0
All shared boards	41		0

CodingLike-for-likeSix of these boards feed the Vibe Coding Index100

Coding benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
LiveBench coding	78.5%	Not measured	Only Gemini 4 Hydrogen measured
LMArena WebDev	1704	1519	Gemini 4 Hydrogen
AA Coding Index	Not measured	71.4	Only GPT-5.6 Luna measured
SWE-bench Verified (Vals AI)	Not measured	93.0%	Only GPT-5.6 Luna measured
Terminal-Bench 4 (Vals AI)	54.0%	11.6%	Gemini 4 Hydrogen
Vibe Code Bench (Vals AI)	87.8%	77.1%	Gemini 4 Hydrogen
Code migration (Vals AI)	Not measured	44.5%	Only GPT-5.6 Luna measured
ProgramBench (Vals AI)	Not measured	0.0%	Only GPT-5.6 Luna measured
IOI (Vals AI)	Not measured	61.8%	Only GPT-5.6 Luna measured
Terminal-Bench 2.1 (Vals AI)	Not measured	79.0%	Only GPT-5.6 Luna measured
Vibe Code Bench 1-100 (Vals AI)	Not measured	22.6%	Only GPT-5.6 Luna measured
SkillsBench (Vals AI)	Not measured	60.5%	Only GPT-5.6 Luna measured
CyberBench (Vals AI)	Not measured	73.6%	Only GPT-5.6 Luna measured
SciCode	Not measured	53.6%	Only GPT-5.6 Luna measured
Terminal-Bench 4.0 (Artificial Analysis run)	54.0%	11.6%	Gemini 4 Hydrogen
FrontierCode 2.0	39.0%	17.6%	Gemini 4 Hydrogen
FrontierCode	Not measured	39.8%	Only GPT-5.6 Luna measured
WeirdML	Not measured	60.9%	Only GPT-5.6 Luna measured
MirrorCode	Not measured	21.1%	Only GPT-5.6 Luna measured
ALE-Bench	Not measured	1667.4	Only GPT-5.6 Luna measured
LMArena Text: coding	1516	1467	Gemini 4 Hydrogen
LMArena Text: software and IT	1513	1464	Gemini 4 Hydrogen
LMArena WebDev: React	1724	1508	Gemini 4 Hydrogen
LMArena WebDev: HTML	1743	1522	Gemini 4 Hydrogen
LMArena WebDev: from an image	Not measured	1517	Only GPT-5.6 Luna measured
SciCode	Not measured	6.2%	Only GPT-5.6 Luna measured
GameBench 2	Not measured	54.0	Only GPT-5.6 Luna measured
Terminal-Bench 2.1	Not measured	75.7%	Only GPT-5.6 Luna measured
Terminal-Bench 3.0	Not measured	14.3%	Only GPT-5.6 Luna measured
Terminal-Bench 4.0	Not measured	17.3%	Only GPT-5.6 Luna measured
CursorBench 4.0	57.8%	35.9%	Gemini 4 Hydrogen
Neither model has a result on the other 21 boards here

IntelligenceDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared

Intelligence benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
AA Intelligence Index	Not measured	23.8	Only GPT-5.6 Luna measured
Epoch Capabilities Index	Not measured	156.7	Only GPT-5.6 Luna measured

Agentic workLike-for-likePublic boards, shown as published, kept out of the index20

Agentic work benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
AA Agentic Index	Not measured	42.1	Only GPT-5.6 Luna measured
LiveBench research	86.8%	Not measured	Only Gemini 4 Hydrogen measured
LiveBench browser	77.1%	Not measured	Only Gemini 4 Hydrogen measured
LiveBench long agentic	61.8%	Not measured	Only Gemini 4 Hydrogen measured
SREBench (Vals AI)	Not measured	1.5%	Only GPT-5.6 Luna measured
Finance Agent (Vals AI)	Not measured	55.0%	Only GPT-5.6 Luna measured
Tax Agent Bench (Vals AI)	52.3%	24.8%	Gemini 4 Hydrogen
Legal Research Bench (Vals AI)	53.8%	36.5%	Gemini 4 Hydrogen
Harvey's Legal Agent Benchmark (Vals AI)	11.3%	Not measured	Only Gemini 4 Hydrogen measured
Excel Modeling Benchmark (Vals AI)	Not measured	67.1%	Only GPT-5.6 Luna measured
BioMysteryBench (Vals AI)	Not measured	61.5%	Only GPT-5.6 Luna measured
Terminal-Bench-Science (Vals AI)	Not measured	0.0%	Only GPT-5.6 Luna measured
Vals Science Index	Not measured	25.3%	Only GPT-5.6 Luna measured
APEX-Agents	Not measured	43.0%	Only GPT-5.6 Luna measured
BALROG	Not measured	45.6%	Only GPT-5.6 Luna measured
Vending-Bench 2	Not measured	$4,095	Only GPT-5.6 Luna measured
Neither model has a result on the other 28 boards here

ReasoningLike-for-likePublic boards, shown as published, kept out of the index50

Reasoning benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
GPQA Diamond	Not measured	91.7%	Only GPT-5.6 Luna measured
LiveBench reasoning	88.6%	Not measured	Only Gemini 4 Hydrogen measured
MysteryMechanism (Vals AI)	Not measured	14.4%	Only GPT-5.6 Luna measured
MMMU Pro (Vals AI)	Not measured	85.0%	Only GPT-5.6 Luna measured
GPQA Diamond (Artificial Analysis run)	Not measured	91.1%	Only GPT-5.6 Luna measured
Humanity's Last Exam (Artificial Analysis run)	Not measured	39.5%	Only GPT-5.6 Luna measured
HLE-Diamond (Artificial Analysis run)	58.8%	20.9%	Gemini 4 Hydrogen
CritPt v2, hard subset (Artificial Analysis run)	66.0%	30.5%	Gemini 4 Hydrogen
GPQA Diamond (Epoch AI run)	Not measured	91.6%	Only GPT-5.6 Luna measured
ARC-AGI	Not measured	88.0%	Only GPT-5.6 Luna measured
ARC-AGI-2	Not measured	59.5%	Only GPT-5.6 Luna measured
SimpleBench	Not measured	46.8%	Only GPT-5.6 Luna measured
Chess puzzles	Not measured	43.0%	Only GPT-5.6 Luna measured
Mystery game puzzles	Not measured	21.0%	Only GPT-5.6 Luna measured
LMArena Text: hard prompts	1520	1452	Gemini 4 Hydrogen
LMArena Text: expert	1558	1477	Gemini 4 Hydrogen
LMArena Text: hard prompts in English	1514	1460	Gemini 4 Hydrogen
LMArena Vision: diagrams	Not measured	1271	Only GPT-5.6 Luna measured
LMArena Vision: homework	Not measured	1281	Only GPT-5.6 Luna measured
Kagi LLM Benchmark	Not measured	49.1%	Only GPT-5.6 Luna measured
GoBench	Not measured	1091	Only GPT-5.6 Luna measured
Neither model has a result on the other 5 boards here

MathLike-for-likePublic boards, shown as published, kept out of the index20

Math benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
OTIS Mock AIME	Not measured	98.3%	Only GPT-5.6 Luna measured
FrontierMath, tiers 1 to 3	Not measured	82.1%	Only GPT-5.6 Luna measured
FrontierMath, tier 4	Not measured	61.0%	Only GPT-5.6 Luna measured
ProofBench	Not measured	60.0%	Only GPT-5.6 Luna measured
LMArena Text: math	1507	1457	Gemini 4 Hydrogen
LMArena Text: mathematical work	1534	1467	Gemini 4 Hydrogen
Neither model has a result on the other 8 boards here

KnowledgeLike-for-likePublic boards, shown as published, kept out of the index50

Knowledge benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
MMLU Pro	Not measured	86.0%	Only GPT-5.6 Luna measured
LegalBench (Vals AI)	Not measured	84.0%	Only GPT-5.6 Luna measured
CorpFin (Vals AI)	Not measured	64.2%	Only GPT-5.6 Luna measured
TaxEval (Vals AI)	Not measured	76.2%	Only GPT-5.6 Luna measured
MortgageTax (Vals AI)	Not measured	67.3%	Only GPT-5.6 Luna measured
MedCode (Vals AI)	Not measured	42.4%	Only GPT-5.6 Luna measured
AA-Omniscience	46.3	-17.1	Gemini 4 Hydrogen
SimpleQA Verified	Not measured	41.0%	Only GPT-5.6 Luna measured
LMArena Text: science	1519	1434	Gemini 4 Hydrogen
LMArena Text: medicine and healthcare	1488	1399	Gemini 4 Hydrogen
LMArena Text: legal and government	1532	1444	Gemini 4 Hydrogen
LMArena Text: business and finance	1486	1439	Gemini 4 Hydrogen
FACTS Benchmark Suite	Not measured	56.9%	Only GPT-5.6 Luna measured
Neither model has a result on the other 8 boards here

Web designLike-for-likePublic boards, shown as published, kept out of the index40

Web design benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
Design Arena: websites	1320	1248	Gemini 4 Hydrogen
Design Arena: UI components	Not measured	1241	Only GPT-5.6 Luna measured
Design Arena: game dev	1369	1190	Gemini 4 Hydrogen
Design Arena: data viz	Not measured	1203	Only GPT-5.6 Luna measured
Design Arena: 3D	1415	1099	Gemini 4 Hydrogen
Design Arena: all code categories	1333	1221	Gemini 4 Hydrogen
Design Arena: SVG	Not measured	1185	Only GPT-5.6 Luna measured
Design Arena: ASCII art	Not measured	1142	Only GPT-5.6 Luna measured
LiveBench design	77.3%	Not measured	Only Gemini 4 Hydrogen measured

GeneralLike-for-likePublic boards, shown as published, kept out of the index130

General benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
Vals Index	68.5%	Not measured	Only Gemini 4 Hydrogen measured
LiveBench data analysis	83.2%	Not measured	Only Gemini 4 Hydrogen measured
Public Benefits Bench (Vals AI)	Not measured	61.2%	Only GPT-5.6 Luna measured
MedScribe (Vals AI)	Not measured	84.4%	Only GPT-5.6 Luna measured
Vals Multimodal Index	Not measured	69.1%	Only GPT-5.6 Luna measured
Long context reasoning (AA-LCR)	Not measured	83.7%	Only GPT-5.6 Luna measured
GDPval-AA	Not measured	1470	Only GPT-5.6 Luna measured
DTBench	Not measured	89.1%	Only GPT-5.6 Luna measured
LMCA	Not measured	48.5%	Only GPT-5.6 Luna measured
Surface Evolver Bench	Not measured	61.9%	Only GPT-5.6 Luna measured
Furniture assembly	Not measured	42.5%	Only GPT-5.6 Luna measured
LMArena Text	1502	1431	Gemini 4 Hydrogen
LMArena Text: instruction following	1519	1437	Gemini 4 Hydrogen
LMArena Text: creative writing	1509	1396	Gemini 4 Hydrogen
LMArena Vision	Not measured	1256	Only GPT-5.6 Luna measured
LMArena Text: English	1499	1442	Gemini 4 Hydrogen
LMArena Text: non-English	1495	1417	Gemini 4 Hydrogen
LMArena Text: Chinese	1631	1472	Gemini 4 Hydrogen
LMArena Text: German	Not measured	1456	Only GPT-5.6 Luna measured
LMArena Text: Japanese	Not measured	1416	Only GPT-5.6 Luna measured
LMArena Text: Korean	Not measured	1408	Only GPT-5.6 Luna measured
LMArena Text: French	1512	1454	Gemini 4 Hydrogen
LMArena Text: Spanish	1494	1448	Gemini 4 Hydrogen
LMArena Text: Russian	1492	1426	Gemini 4 Hydrogen
LMArena Text: Polish	Not measured	1403	Only GPT-5.6 Luna measured
LMArena Text: multi-turn	1485	1434	Gemini 4 Hydrogen
LMArena Text: longer queries	1524	1436	Gemini 4 Hydrogen
LMArena Text: writing and language	1500	1418	Gemini 4 Hydrogen
LMArena Text: entertainment and media	1503	1401	Gemini 4 Hydrogen
LMArena Vision: English	Not measured	1260	Only GPT-5.6 Luna measured
LMArena Vision: Chinese	Not measured	1301	Only GPT-5.6 Luna measured
LMArena Vision: reading text	Not measured	1263	Only GPT-5.6 Luna measured
LMArena Vision: humor	Not measured	1192	Only GPT-5.6 Luna measured
LMArena Vision: creative writing	Not measured	1256	Only GPT-5.6 Luna measured
LMArena Document	Not measured	1454	Only GPT-5.6 Luna measured
EQ-Bench 4	Not measured	1146	Only GPT-5.6 Luna measured
Neither model has a result on the other 13 boards here

Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared

Image generation benchmarks for Gemini 4 Hydrogen and GPT-5.6 Luna
Benchmark	Gemini 4 Hydrogen	GPT-5.6 Luna	Leader
Neither model has a result on 5 boards here

What each workload costs

Three fixed token mixes at each model's listed price, so per-token rates become a bill.

Chat turn

1K input + 500 output tokens

Gemini 4 Hydrogen$0.0053Fits in one request

GPT-5.6 Luna$0.0008Fits in one request

GPT-5.6 Luna costs less

Repository review

50K input + 3K output tokens

Gemini 4 Hydrogen$0.098Fits in one request

GPT-5.6 Luna$0.014Fits in one request

GPT-5.6 Luna costs less

Agent loop

200K input + 10K output tokens

Gemini 4 Hydrogen$0.375Fits in one request

GPT-5.6 Luna$0.052Fits in one request

GPT-5.6 Luna costs less

Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.

Specification differences

The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.

Specifications of Gemini 4 Hydrogen and GPT-5.6 Luna
Specification	Google Gemini 4 Hydrogen	OpenAI GPT-5.6 Luna
Maker	Google	OpenAI
Weights	No public weights listed	No public weights listed
Released	November 12, 2026	July 9, 2026
Context window	1.05M	1.05M
Input $/Mtok	$1.50	$0.20
Output $/Mtok	$7.50	$1.20
Coding index	77.9	55.3
Independent measurements behind it	4	5
Cost per solved task	Not computable	$0.04
Source	OpenRouter listing	OpenRouter listing

Questions

Is Gemini 4 Hydrogen better than GPT-5.6 Luna for coding?

Pick Gemini 4 Hydrogen for coding: it scores 77.9 on the Vibe Coding Index against 55.3 for GPT-5.6 Luna, though on 4 benchmarks against 5. Pick GPT-5.6 Luna for output tokens 6.3x cheaper ($1.20 vs $7.50 per million) and a larger context window (1.05M against 1.05M tokens).

Which is cheaper, Gemini 4 Hydrogen or GPT-5.6 Luna?

Gemini 4 Hydrogen costs $1.50 per million input tokens and $7.50 per million output tokens; GPT-5.6 Luna costs $0.20 and $1.20. Cost per solved task is known for GPT-5.6 Luna only.

Which has the bigger context window, Gemini 4 Hydrogen or GPT-5.6 Luna?

GPT-5.6 Luna, with 1.05M tokens against 1.05M.

How many benchmarks is the Gemini 4 Hydrogen vs GPT-5.6 Luna comparison based on?

41 benchmarks have a result for both models as of November 14, 2026. Gemini 4 Hydrogen's coding index rests on 4 independent benchmarks and GPT-5.6 Luna's on 5. Where only one model has a result, the page says so instead of naming a winner.

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Gemini 4 Hydrogen or GPT-5.6 Luna: which to pick

Which one for your work

Coding

Intelligence

Agentic work

Reasoning

Knowledge

Web design

General

Long documents

Everyday cost

Cost per solved task

At a glance

Benchmark by benchmark

What each workload costs

Chat turn

Repository review

Agent loop

Specification differences

Questions

Compare next